An ad hoc network is a self-configuring network of mobile nodes connected by links. A node in the network may be free to move independently in any direction, and may change its link to other nodes frequently. When a first node tries to establish a link with a second node, the first node may transmit a first message to the second node. In response to the first message, the second node may transmit a second message back to the first node to confirm receipt of the first message. A link may be established after the first node receives the second message.
The second node, however, may not be able to respond the first message when the second node is already exchanging information with a third node in the network. The failure of not responding the first message may result in inefficiencies of the network.